Low-friction Carbo AirBlocks® are lightweight, strong, reliable—and affordable. Companions to the popular Harken® Black Magic® line, these small, compact blocks have very high working loads for safe, easy trimming. We aim to ship Pre Order Harken Parts within a week of purchase.  Sheave Ø (mm)75 mm Length (mm)152 mm Weight (g)402 g Shackle pin Ø (mm)8 mm Maximum line Ø (mm)14 mm Maximum working load (kg)1100 kg Breaking load (kg)2722 kg